Assuming that your CONTROL_FILE_RECORD_KEEP_TIME is set to default value of 7, your are hitting the max value(65535) MAXLOGHISTORY.

You can set CONTROL_FILE_RECORD_KEEP_TIME to 0 either in init.ora or dynamically alter system set control_file_record_keep_time=0;

Check Metalink for more info.

HTH
Sanjay